WP3 – Neuromodulation Therapies

Neuromodulation surgical techniques has been used to treat rCP for nearly 50 years. Many aspects remain unknown or controversial, including mechanisms of action of these techniques, selection criteria of candidate patients, diffusion of the techniques and their reimbursement/funding conditions. This work package addresses these points through 5 tasks.

Task 1: Clinical studies (D Fontaine, M Lanteri-Minet)

¤ Occipital Nerve Stimulation (ONS) patients cohort (“Observatoire de l’ONS”). We follow-up, analyze and publish the data concerning the epidemiology of patients undergoing ONS for primary headache, their outcome, the surgical complications and cost-effectiveness based on our database.

¤ “DOSE CLUSTIM” Study: A randomized controlled trial (RCT) studies the efficacy of several ONS stimulation parameters. It is promoted by our center and co-funded by St Jude.

¤ EMOPAIN Study: We explore a new therapeutic solution in a pilot study evaluating the outcome with classical pain scores but also with multidimensional scales exploring behavior and emotion (team R8 LAPCOS). This study is proposed for funding by our CHU and is cofunded by St Jude Medical. Ancillary studies aiming to enhance our understanding of emotional processing of pain will be developed in tasks 3 and 4.

¤ PNS studies. We collaborate with Axonic to conceptualize and set up pilot studies evaluating peripheral nerve stimulation devices developed by this company, especially in post surgical neuropathic pain topographically limited.

Task 2: Selection (D Fontaine, S Faure)

The aim of Task 2 is to elaborate a common and relevant psycho-social assessment protocol and objective criteria for SCS contra-indication, through a consensus process assisted by litterature review and French pain experts survey. This is conducted in collaboration with 2 scientific societies (the French chapters of the IASP and International Neuromodulation Society).

In a second step, a similar process is conducted for ONS and PNS.

Task 3: Modeling

- Statistical modeling (F Grammont, P Reynaud-Bouret) The first goal is to use statistical modeling and machine learning techniques (team R7) in order to propose to physicians the shortest way to find the best stimulation patterns for each patient, as a function of his reactions to stimulations. The second goal is to elaborate more physiological patterns of stimulation, being more efficient to propagate into nervous tissues and more economical in power consumption. This task is conducted in collaboration with Medtronic and I3S (UMR CNRS 6070).

- Ex-vivo exploration (M Studer, F Grammont) We aim to better understand how electrical stimulations propagate into central and peripheral nervous tissues, and to test specific patterns of stimulation, to elaborate statistical models on mice ex-vivo preparations, before testing them on patients.

- DBS modeling in pain In a second step, we develop a rodent model of cingulate cortex chronic stimulation to study the biological effects of cingulate DBS.

Task 4: Neuroimaging. (J Darcourt, R Deriche)

We coordinate the METONS study, exploring brain metabolism changes by PET scan in CCH patients treated by ONS. Complementary neuroimaging studies are conducted in patients included in the EMOPAIN study (see Task 1).

A study combining PET, functional and diffusion MRI explores resting-state brain activity and structural connectivity to identify brain networks involved in the rCP state and their changes.

Task 5: Regulations and diffusion. (D Fontaine)

In relation with regulatory authorities and scientific societies (French chapters of the IASP and INS), Task 5 endeavors to obtain recognition and/or funding for new neuromodulation techniques or management of care.